When such apparatus is operated manually, organic substances stuck to the crucible from the hands of the operator if he grasps the crucible with his hands lead to errors in analysis. Accordingly, the operation is made more difficult since the operator must grasp the crucible with pincers.
To avoid this, one apparatus of this type, for example the apparatus disclosed in U.S. Pat. No. 4,238,450, has been partly automated. However, only the introduction of a crucible into a combustion furnace and the discharge of the crucible from the combustion furnace is automated.